213231421 has 16 divisors (see below), whose sum is σ = 232848000. Its totient is φ = 194096448.

The previous prime is 213231397. The next prime is 213231427. The reversal of 213231421 is 124132312.

It is a happy number.

It is not a de Polignac number, because 213231421 - 2¹³ = 213223229 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (213231427) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 355680 + ... + 356278.

It is an arithmetic number, because the mean of its divisors is an integer number (14553000).

Almost surely, 2^213231421 is an apocalyptic number.

It is an amenable number.

213231421 is a deficient number, since it is larger than the sum of its proper divisors (19616579).

213231421 is a wasteful number, since it uses less digits than its factorization.

213231421 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 948.

The product of its digits is 288, while the sum is 19.

The square root of 213231421 is about 14602.4457198101. The cubic root of 213231421 is about 597.4254697161.

Adding to 213231421 its reverse (124132312), we get a palindrome (337363733).

The spelling of 213231421 in words is "two hundred thirteen million, two hundred thirty-one thousand, four hundred twenty-one".